Multiplayer
If there's a downside to Baldur's Gate it's the multiplayer aspect. If you're expecting it to vary from the single player game by adding more monsters to kill you should realize that it's basically the same thing as playing single player. The only difference is that human players control your party members. That wouldn't be so bad, except for the fact that the multiplayer game sticks strictly by party based movement and activity. What that means is that if one player in your party stops to talk to a shopkeeper, EVERYONE in the game must stop and listen in on the conversation. If a cut scene interrupts the game, EVERYONE in the game has to stop and watch or wait for others to watch or cancel the cinema. There isn't much in the way of independent action, because the party leader is largely in control of everything. You can imagine that if the game has the maximum 6 human players in the party, things can get chaotic. Also, the gold in the party is pooled so you have to negotiate with your teammates on who should get which kind of items.

Narrated sequences occasionally
happen during rest time
I can see how multiplayer could be fun if it was limited to two people who know what they're doing, and preferably, are already friends with one another. Three players is pushing the limits of feasibility, unless you're all in the same room and can talk/shout to one another without wasting time by talking with the chat box. But overall it's difficult for me to see how 4-6 complete strangers can make a cooperative multiplayer game work. It's bad enough in some games when you have to deal with people who are not carrying their load or what not but at least you have some semblance of independence. In Baldur's Gate, the party based system doesn't really make for an easy to set up multiplayer experience.

You'll see a lot of this screen
if you have a slow CD ROM
Baldur's Gate works with GameSpy to help find open servers on the internet. It must work pretty well at finding games when you consider what happened the first time we fired up a multiplayer game of BG. We were playing TCP/IP over our LAN but a couple of the players left their modem connection on. Boy were we surprised with some random guy named "davood" jumped into our game off of the internet! I asked him if he found us through GameSpy and the answer was "yup." We learned quickly to close off our games to unwanted players. =) Just be careful when setting up a multiplayer game because a couple of times it hung up our computers when we tried to join up a game. It's hard to say whether it's the game's fault or the fault of our LAN but between all our War2, Quake, Quake2, and Starcraft gaming, we've never had a game freeze our system when setting up a multiplayer match.
Other lowpoints
Other than the multiplayer there are other minor issues that are somewhat annoying. The pathing AI leaves a lot to be desired. Also, when purchasing items, there's no real way to specify the number of items you want which would have been nice. I also got some minor audio bugs while using my MX200 sound card but those went away once I updated the drivers.